xref: /linux/net/mac80211/ht.c (revision 1e6d11fe72e311c1989991ee318d239f650fa318)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * HT handling
4  *
5  * Copyright 2003, Jouni Malinen <jkmaline@cc.hut.fi>
6  * Copyright 2002-2005, Instant802 Networks, Inc.
7  * Copyright 2005-2006, Devicescape Software, Inc.
8  * Copyright 2006-2007	Jiri Benc <jbenc@suse.cz>
9  * Copyright 2007, Michael Wu <flamingice@sourmilk.net>
10  * Copyright 2007-2010, Intel Corporation
11  * Copyright 2017	Intel Deutschland GmbH
12  * Copyright(c) 2020-2022 Intel Corporation
13  */
14 
15 #include <linux/ieee80211.h>
16 #include <linux/export.h>
17 #include <net/mac80211.h>
18 #include "ieee80211_i.h"
19 #include "rate.h"
20 
21 static void __check_htcap_disable(struct ieee80211_ht_cap *ht_capa,
22 				  struct ieee80211_ht_cap *ht_capa_mask,
23 				  struct ieee80211_sta_ht_cap *ht_cap,
24 				  u16 flag)
25 {
26 	__le16 le_flag = cpu_to_le16(flag);
27 	if (ht_capa_mask->cap_info & le_flag) {
28 		if (!(ht_capa->cap_info & le_flag))
29 			ht_cap->cap &= ~flag;
30 	}
31 }
32 
33 static void __check_htcap_enable(struct ieee80211_ht_cap *ht_capa,
34 				  struct ieee80211_ht_cap *ht_capa_mask,
35 				  struct ieee80211_sta_ht_cap *ht_cap,
36 				  u16 flag)
37 {
38 	__le16 le_flag = cpu_to_le16(flag);
39 
40 	if ((ht_capa_mask->cap_info & le_flag) &&
41 	    (ht_capa->cap_info & le_flag))
42 		ht_cap->cap |= flag;
43 }
44 
45 void ieee80211_apply_htcap_overrides(struct ieee80211_sub_if_data *sdata,
46 				     struct ieee80211_sta_ht_cap *ht_cap)
47 {
48 	struct ieee80211_ht_cap *ht_capa, *ht_capa_mask;
49 	u8 *scaps, *smask;
50 	int i;
51 
52 	if (!ht_cap->ht_supported)
53 		return;
54 
55 	switch (sdata->vif.type) {
56 	case NL80211_IFTYPE_STATION:
57 		ht_capa = &sdata->u.mgd.ht_capa;
58 		ht_capa_mask = &sdata->u.mgd.ht_capa_mask;
59 		break;
60 	case NL80211_IFTYPE_ADHOC:
61 		ht_capa = &sdata->u.ibss.ht_capa;
62 		ht_capa_mask = &sdata->u.ibss.ht_capa_mask;
63 		break;
64 	default:
65 		WARN_ON_ONCE(1);
66 		return;
67 	}
68 
69 	scaps = (u8 *)(&ht_capa->mcs.rx_mask);
70 	smask = (u8 *)(&ht_capa_mask->mcs.rx_mask);
71 
72 	/* NOTE:  If you add more over-rides here, update register_hw
73 	 * ht_capa_mod_mask logic in main.c as well.
74 	 * And, if this method can ever change ht_cap.ht_supported, fix
75 	 * the check in ieee80211_add_ht_ie.
76 	 */
77 
78 	/* check for HT over-rides, MCS rates first. */
79 	for (i = 0; i < IEEE80211_HT_MCS_MASK_LEN; i++) {
80 		u8 m = smask[i];
81 		ht_cap->mcs.rx_mask[i] &= ~m; /* turn off all masked bits */
82 		/* Add back rates that are supported */
83 		ht_cap->mcs.rx_mask[i] |= (m & scaps[i]);
84 	}
85 
86 	/* Force removal of HT-40 capabilities? */
87 	__check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
88 			      IEEE80211_HT_CAP_SUP_WIDTH_20_40);
89 	__check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
90 			      IEEE80211_HT_CAP_SGI_40);
91 
92 	/* Allow user to disable SGI-20 (SGI-40 is handled above) */
93 	__check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
94 			      IEEE80211_HT_CAP_SGI_20);
95 
96 	/* Allow user to disable the max-AMSDU bit. */
97 	__check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
98 			      IEEE80211_HT_CAP_MAX_AMSDU);
99 
100 	/* Allow user to disable LDPC */
101 	__check_htcap_disable(ht_capa, ht_capa_mask, ht_cap,
102 			      IEEE80211_HT_CAP_LDPC_CODING);
103 
104 	/* Allow user to enable 40 MHz intolerant bit. */
105 	__check_htcap_enable(ht_capa, ht_capa_mask, ht_cap,
106 			     IEEE80211_HT_CAP_40MHZ_INTOLERANT);
107 
108 	/* Allow user to enable TX STBC bit  */
109 	__check_htcap_enable(ht_capa, ht_capa_mask, ht_cap,
110 			     IEEE80211_HT_CAP_TX_STBC);
111 
112 	/* Allow user to configure RX STBC bits */
113 	if (ht_capa_mask->cap_info & cpu_to_le16(IEEE80211_HT_CAP_RX_STBC))
114 		ht_cap->cap |= le16_to_cpu(ht_capa->cap_info) &
115 					IEEE80211_HT_CAP_RX_STBC;
116 
117 	/* Allow user to decrease AMPDU factor */
118 	if (ht_capa_mask->ampdu_params_info &
119 	    IEEE80211_HT_AMPDU_PARM_FACTOR) {
120 		u8 n = ht_capa->ampdu_params_info &
121 		       IEEE80211_HT_AMPDU_PARM_FACTOR;
122 		if (n < ht_cap->ampdu_factor)
123 			ht_cap->ampdu_factor = n;
124 	}
125 
126 	/* Allow the user to increase AMPDU density. */
127 	if (ht_capa_mask->ampdu_params_info &
128 	    IEEE80211_HT_AMPDU_PARM_DENSITY) {
129 		u8 n = (ht_capa->ampdu_params_info &
130 			IEEE80211_HT_AMPDU_PARM_DENSITY)
131 			>> IEEE80211_HT_AMPDU_PARM_DENSITY_SHIFT;
132 		if (n > ht_cap->ampdu_density)
133 			ht_cap->ampdu_density = n;
134 	}
135 }
136 
137 
138 bool ieee80211_ht_cap_ie_to_sta_ht_cap(struct ieee80211_sub_if_data *sdata,
139 				       struct ieee80211_supported_band *sband,
140 				       const struct ieee80211_ht_cap *ht_cap_ie,
141 				       struct link_sta_info *link_sta)
142 {
143 	struct ieee80211_bss_conf *link_conf;
144 	struct sta_info *sta = link_sta->sta;
145 	struct ieee80211_sta_ht_cap ht_cap, own_cap;
146 	u8 ampdu_info, tx_mcs_set_cap;
147 	int i, max_tx_streams;
148 	bool changed;
149 	enum ieee80211_sta_rx_bandwidth bw;
150 	enum nl80211_chan_width width;
151 
152 	memset(&ht_cap, 0, sizeof(ht_cap));
153 
154 	if (!ht_cap_ie || !sband->ht_cap.ht_supported)
155 		goto apply;
156 
157 	ht_cap.ht_supported = true;
158 
159 	own_cap = sband->ht_cap;
160 
161 	/*
162 	 * If user has specified capability over-rides, take care
163 	 * of that if the station we're setting up is the AP or TDLS peer that
164 	 * we advertised a restricted capability set to. Override
165 	 * our own capabilities and then use those below.
166 	 */
167 	if (sdata->vif.type == NL80211_IFTYPE_STATION ||
168 	    sdata->vif.type == NL80211_IFTYPE_ADHOC)
169 		ieee80211_apply_htcap_overrides(sdata, &own_cap);
170 
171 	/*
172 	 * The bits listed in this expression should be
173 	 * the same for the peer and us, if the station
174 	 * advertises more then we can't use those thus
175 	 * we mask them out.
176 	 */
177 	ht_cap.cap = le16_to_cpu(ht_cap_ie->cap_info) &
178 		(own_cap.cap | ~(IEEE80211_HT_CAP_LDPC_CODING |
179 				 IEEE80211_HT_CAP_SUP_WIDTH_20_40 |
180 				 IEEE80211_HT_CAP_GRN_FLD |
181 				 IEEE80211_HT_CAP_SGI_20 |
182 				 IEEE80211_HT_CAP_SGI_40 |
183 				 IEEE80211_HT_CAP_DSSSCCK40));
184 
185 	/*
186 	 * The STBC bits are asymmetric -- if we don't have
187 	 * TX then mask out the peer's RX and vice versa.
188 	 */
189 	if (!(own_cap.cap & IEEE80211_HT_CAP_TX_STBC))
190 		ht_cap.cap &= ~IEEE80211_HT_CAP_RX_STBC;
191 	if (!(own_cap.cap & IEEE80211_HT_CAP_RX_STBC))
192 		ht_cap.cap &= ~IEEE80211_HT_CAP_TX_STBC;
193 
194 	ampdu_info = ht_cap_ie->ampdu_params_info;
195 	ht_cap.ampdu_factor =
196 		ampdu_info & IEEE80211_HT_AMPDU_PARM_FACTOR;
197 	ht_cap.ampdu_density =
198 		(ampdu_info & IEEE80211_HT_AMPDU_PARM_DENSITY) >> 2;
199 
200 	/* own MCS TX capabilities */
201 	tx_mcs_set_cap = own_cap.mcs.tx_params;
202 
203 	/* Copy peer MCS TX capabilities, the driver might need them. */
204 	ht_cap.mcs.tx_params = ht_cap_ie->mcs.tx_params;
205 
206 	/* can we TX with MCS rates? */
207 	if (!(tx_mcs_set_cap & IEEE80211_HT_MCS_TX_DEFINED))
208 		goto apply;
209 
210 	/* Counting from 0, therefore +1 */
211 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_RX_DIFF)
212 		max_tx_streams =
213 			((tx_mcs_set_cap & IEEE80211_HT_MCS_TX_MAX_STREAMS_MASK)
214 				>> IEEE80211_HT_MCS_TX_MAX_STREAMS_SHIFT) + 1;
215 	else
216 		max_tx_streams = IEEE80211_HT_MCS_TX_MAX_STREAMS;
217 
218 	/*
219 	 * 802.11n-2009 20.3.5 / 20.6 says:
220 	 * - indices 0 to 7 and 32 are single spatial stream
221 	 * - 8 to 31 are multiple spatial streams using equal modulation
222 	 *   [8..15 for two streams, 16..23 for three and 24..31 for four]
223 	 * - remainder are multiple spatial streams using unequal modulation
224 	 */
225 	for (i = 0; i < max_tx_streams; i++)
226 		ht_cap.mcs.rx_mask[i] =
227 			own_cap.mcs.rx_mask[i] & ht_cap_ie->mcs.rx_mask[i];
228 
229 	if (tx_mcs_set_cap & IEEE80211_HT_MCS_TX_UNEQUAL_MODULATION)
230 		for (i = IEEE80211_HT_MCS_UNEQUAL_MODULATION_START_BYTE;
231 		     i < IEEE80211_HT_MCS_MASK_LEN; i++)
232 			ht_cap.mcs.rx_mask[i] =
233 				own_cap.mcs.rx_mask[i] &
234 					ht_cap_ie->mcs.rx_mask[i];
235 
236 	/* handle MCS rate 32 too */
237 	if (own_cap.mcs.rx_mask[32/8] & ht_cap_ie->mcs.rx_mask[32/8] & 1)
238 		ht_cap.mcs.rx_mask[32/8] |= 1;
239 
240 	/* set Rx highest rate */
241 	ht_cap.mcs.rx_highest = ht_cap_ie->mcs.rx_highest;
242 
243 	if (ht_cap.cap & IEEE80211_HT_CAP_MAX_AMSDU)
244 		sta->sta.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_HT_7935;
245 	else
246 		sta->sta.max_amsdu_len = IEEE80211_MAX_MPDU_LEN_HT_3839;
247 
248  apply:
249 	changed = memcmp(&link_sta->pub->ht_cap, &ht_cap, sizeof(ht_cap));
250 
251 	memcpy(&link_sta->pub->ht_cap, &ht_cap, sizeof(ht_cap));
252 
253 	rcu_read_lock();
254 	link_conf = rcu_dereference(sdata->vif.link_conf[link_sta->link_id]);
255 	if (WARN_ON(!link_conf))
256 		width = NL80211_CHAN_WIDTH_20_NOHT;
257 	else
258 		width = link_conf->chandef.width;
259 
260 	switch (width) {
261 	default:
262 		WARN_ON_ONCE(1);
263 		fallthrough;
264 	case NL80211_CHAN_WIDTH_20_NOHT:
265 	case NL80211_CHAN_WIDTH_20:
266 		bw = IEEE80211_STA_RX_BW_20;
267 		break;
268 	case NL80211_CHAN_WIDTH_40:
269 	case NL80211_CHAN_WIDTH_80:
270 	case NL80211_CHAN_WIDTH_80P80:
271 	case NL80211_CHAN_WIDTH_160:
272 		bw = ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
273 				IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
274 		break;
275 	}
276 	rcu_read_unlock();
277 
278 	link_sta->pub->bandwidth = bw;
279 
280 	link_sta->cur_max_bandwidth =
281 		ht_cap.cap & IEEE80211_HT_CAP_SUP_WIDTH_20_40 ?
282 				IEEE80211_STA_RX_BW_40 : IEEE80211_STA_RX_BW_20;
283 
284 	if (sta->sdata->vif.type == NL80211_IFTYPE_AP ||
285 	    sta->sdata->vif.type == NL80211_IFTYPE_AP_VLAN) {
286 		enum ieee80211_smps_mode smps_mode;
287 
288 		switch ((ht_cap.cap & IEEE80211_HT_CAP_SM_PS)
289 				>> IEEE80211_HT_CAP_SM_PS_SHIFT) {
290 		case WLAN_HT_CAP_SM_PS_INVALID:
291 		case WLAN_HT_CAP_SM_PS_STATIC:
292 			smps_mode = IEEE80211_SMPS_STATIC;
293 			break;
294 		case WLAN_HT_CAP_SM_PS_DYNAMIC:
295 			smps_mode = IEEE80211_SMPS_DYNAMIC;
296 			break;
297 		case WLAN_HT_CAP_SM_PS_DISABLED:
298 			smps_mode = IEEE80211_SMPS_OFF;
299 			break;
300 		}
301 
302 		if (smps_mode != sta->sta.smps_mode)
303 			changed = true;
304 		sta->sta.smps_mode = smps_mode;
305 	} else {
306 		sta->sta.smps_mode = IEEE80211_SMPS_OFF;
307 	}
308 	return changed;
309 }
310 
311 void ieee80211_sta_tear_down_BA_sessions(struct sta_info *sta,
312 					 enum ieee80211_agg_stop_reason reason)
313 {
314 	int i;
315 
316 	mutex_lock(&sta->ampdu_mlme.mtx);
317 	for (i = 0; i <  IEEE80211_NUM_TIDS; i++)
318 		___ieee80211_stop_rx_ba_session(sta, i, WLAN_BACK_RECIPIENT,
319 						WLAN_REASON_QSTA_LEAVE_QBSS,
320 						reason != AGG_STOP_DESTROY_STA &&
321 						reason != AGG_STOP_PEER_REQUEST);
322 
323 	for (i = 0; i <  IEEE80211_NUM_TIDS; i++)
324 		___ieee80211_stop_tx_ba_session(sta, i, reason);
325 	mutex_unlock(&sta->ampdu_mlme.mtx);
326 
327 	/*
328 	 * In case the tear down is part of a reconfigure due to HW restart
329 	 * request, it is possible that the low level driver requested to stop
330 	 * the BA session, so handle it to properly clean tid_tx data.
331 	 */
332 	if(reason == AGG_STOP_DESTROY_STA) {
333 		cancel_work_sync(&sta->ampdu_mlme.work);
334 
335 		mutex_lock(&sta->ampdu_mlme.mtx);
336 		for (i = 0; i < IEEE80211_NUM_TIDS; i++) {
337 			struct tid_ampdu_tx *tid_tx =
338 				rcu_dereference_protected_tid_tx(sta, i);
339 
340 			if (!tid_tx)
341 				continue;
342 
343 			if (test_and_clear_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state))
344 				ieee80211_stop_tx_ba_cb(sta, i, tid_tx);
345 		}
346 		mutex_unlock(&sta->ampdu_mlme.mtx);
347 	}
348 }
349 
350 void ieee80211_ba_session_work(struct work_struct *work)
351 {
352 	struct sta_info *sta =
353 		container_of(work, struct sta_info, ampdu_mlme.work);
354 	struct tid_ampdu_tx *tid_tx;
355 	bool blocked;
356 	int tid;
357 
358 	/* When this flag is set, new sessions should be blocked. */
359 	blocked = test_sta_flag(sta, WLAN_STA_BLOCK_BA);
360 
361 	mutex_lock(&sta->ampdu_mlme.mtx);
362 	for (tid = 0; tid < IEEE80211_NUM_TIDS; tid++) {
363 		if (test_and_clear_bit(tid, sta->ampdu_mlme.tid_rx_timer_expired))
364 			___ieee80211_stop_rx_ba_session(
365 				sta, tid, WLAN_BACK_RECIPIENT,
366 				WLAN_REASON_QSTA_TIMEOUT, true);
367 
368 		if (test_and_clear_bit(tid,
369 				       sta->ampdu_mlme.tid_rx_stop_requested))
370 			___ieee80211_stop_rx_ba_session(
371 				sta, tid, WLAN_BACK_RECIPIENT,
372 				WLAN_REASON_UNSPECIFIED, true);
373 
374 		if (!blocked &&
375 		    test_and_clear_bit(tid,
376 				       sta->ampdu_mlme.tid_rx_manage_offl))
377 			___ieee80211_start_rx_ba_session(sta, 0, 0, 0, 1, tid,
378 							 IEEE80211_MAX_AMPDU_BUF_HT,
379 							 false, true, NULL);
380 
381 		if (test_and_clear_bit(tid + IEEE80211_NUM_TIDS,
382 				       sta->ampdu_mlme.tid_rx_manage_offl))
383 			___ieee80211_stop_rx_ba_session(
384 				sta, tid, WLAN_BACK_RECIPIENT,
385 				0, false);
386 
387 		spin_lock_bh(&sta->lock);
388 
389 		tid_tx = sta->ampdu_mlme.tid_start_tx[tid];
390 		if (!blocked && tid_tx) {
391 			/*
392 			 * Assign it over to the normal tid_tx array
393 			 * where it "goes live".
394 			 */
395 
396 			sta->ampdu_mlme.tid_start_tx[tid] = NULL;
397 			/* could there be a race? */
398 			if (sta->ampdu_mlme.tid_tx[tid])
399 				kfree(tid_tx);
400 			else
401 				ieee80211_assign_tid_tx(sta, tid, tid_tx);
402 			spin_unlock_bh(&sta->lock);
403 
404 			ieee80211_tx_ba_session_handle_start(sta, tid);
405 			continue;
406 		}
407 		spin_unlock_bh(&sta->lock);
408 
409 		tid_tx = rcu_dereference_protected_tid_tx(sta, tid);
410 		if (!tid_tx)
411 			continue;
412 
413 		if (!blocked &&
414 		    test_and_clear_bit(HT_AGG_STATE_START_CB, &tid_tx->state))
415 			ieee80211_start_tx_ba_cb(sta, tid, tid_tx);
416 		if (test_and_clear_bit(HT_AGG_STATE_WANT_STOP, &tid_tx->state))
417 			___ieee80211_stop_tx_ba_session(sta, tid,
418 							AGG_STOP_LOCAL_REQUEST);
419 		if (test_and_clear_bit(HT_AGG_STATE_STOP_CB, &tid_tx->state))
420 			ieee80211_stop_tx_ba_cb(sta, tid, tid_tx);
421 	}
422 	mutex_unlock(&sta->ampdu_mlme.mtx);
423 }
424 
425 void ieee80211_send_delba(struct ieee80211_sub_if_data *sdata,
426 			  const u8 *da, u16 tid,
427 			  u16 initiator, u16 reason_code)
428 {
429 	struct ieee80211_local *local = sdata->local;
430 	struct sk_buff *skb;
431 	struct ieee80211_mgmt *mgmt;
432 	u16 params;
433 
434 	skb = dev_alloc_skb(sizeof(*mgmt) + local->hw.extra_tx_headroom);
435 	if (!skb)
436 		return;
437 
438 	skb_reserve(skb, local->hw.extra_tx_headroom);
439 	mgmt = skb_put_zero(skb, 24);
440 	memcpy(mgmt->da, da, ETH_ALEN);
441 	memcpy(mgmt->sa, sdata->vif.addr, ETH_ALEN);
442 	if (sdata->vif.type == NL80211_IFTYPE_AP ||
443 	    sdata->vif.type == NL80211_IFTYPE_AP_VLAN ||
444 	    sdata->vif.type == NL80211_IFTYPE_MESH_POINT)
445 		memcpy(mgmt->bssid, sdata->vif.addr, ETH_ALEN);
446 	else if (sdata->vif.type == NL80211_IFTYPE_STATION)
447 		memcpy(mgmt->bssid, sdata->deflink.u.mgd.bssid, ETH_ALEN);
448 	else if (sdata->vif.type == NL80211_IFTYPE_ADHOC)
449 		memcpy(mgmt->bssid, sdata->u.ibss.bssid, ETH_ALEN);
450 
451 	mgmt->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
452 					  IEEE80211_STYPE_ACTION);
453 
454 	skb_put(skb, 1 + sizeof(mgmt->u.action.u.delba));
455 
456 	mgmt->u.action.category = WLAN_CATEGORY_BACK;
457 	mgmt->u.action.u.delba.action_code = WLAN_ACTION_DELBA;
458 	params = (u16)(initiator << 11); 	/* bit 11 initiator */
459 	params |= (u16)(tid << 12); 		/* bit 15:12 TID number */
460 
461 	mgmt->u.action.u.delba.params = cpu_to_le16(params);
462 	mgmt->u.action.u.delba.reason_code = cpu_to_le16(reason_code);
463 
464 	ieee80211_tx_skb(sdata, skb);
465 }
466 
467 void ieee80211_process_delba(struct ieee80211_sub_if_data *sdata,
468 			     struct sta_info *sta,
469 			     struct ieee80211_mgmt *mgmt, size_t len)
470 {
471 	u16 tid, params;
472 	u16 initiator;
473 
474 	params = le16_to_cpu(mgmt->u.action.u.delba.params);
475 	tid = (params & IEEE80211_DELBA_PARAM_TID_MASK) >> 12;
476 	initiator = (params & IEEE80211_DELBA_PARAM_INITIATOR_MASK) >> 11;
477 
478 	ht_dbg_ratelimited(sdata, "delba from %pM (%s) tid %d reason code %d\n",
479 			   mgmt->sa, initiator ? "initiator" : "recipient",
480 			   tid,
481 			   le16_to_cpu(mgmt->u.action.u.delba.reason_code));
482 
483 	if (initiator == WLAN_BACK_INITIATOR)
484 		__ieee80211_stop_rx_ba_session(sta, tid, WLAN_BACK_INITIATOR, 0,
485 					       true);
486 	else
487 		__ieee80211_stop_tx_ba_session(sta, tid, AGG_STOP_PEER_REQUEST);
488 }
489 
490 enum nl80211_smps_mode
491 ieee80211_smps_mode_to_smps_mode(enum ieee80211_smps_mode smps)
492 {
493 	switch (smps) {
494 	case IEEE80211_SMPS_OFF:
495 		return NL80211_SMPS_OFF;
496 	case IEEE80211_SMPS_STATIC:
497 		return NL80211_SMPS_STATIC;
498 	case IEEE80211_SMPS_DYNAMIC:
499 		return NL80211_SMPS_DYNAMIC;
500 	default:
501 		return NL80211_SMPS_OFF;
502 	}
503 }
504 
505 int ieee80211_send_smps_action(struct ieee80211_sub_if_data *sdata,
506 			       enum ieee80211_smps_mode smps, const u8 *da,
507 			       const u8 *bssid)
508 {
509 	struct ieee80211_local *local = sdata->local;
510 	struct sk_buff *skb;
511 	struct ieee80211_mgmt *action_frame;
512 
513 	/* 27 = header + category + action + smps mode */
514 	skb = dev_alloc_skb(27 + local->hw.extra_tx_headroom);
515 	if (!skb)
516 		return -ENOMEM;
517 
518 	skb_reserve(skb, local->hw.extra_tx_headroom);
519 	action_frame = skb_put(skb, 27);
520 	memcpy(action_frame->da, da, ETH_ALEN);
521 	memcpy(action_frame->sa, sdata->dev->dev_addr, ETH_ALEN);
522 	memcpy(action_frame->bssid, bssid, ETH_ALEN);
523 	action_frame->frame_control = cpu_to_le16(IEEE80211_FTYPE_MGMT |
524 						  IEEE80211_STYPE_ACTION);
525 	action_frame->u.action.category = WLAN_CATEGORY_HT;
526 	action_frame->u.action.u.ht_smps.action = WLAN_HT_ACTION_SMPS;
527 	switch (smps) {
528 	case IEEE80211_SMPS_AUTOMATIC:
529 	case IEEE80211_SMPS_NUM_MODES:
530 		WARN_ON(1);
531 		fallthrough;
532 	case IEEE80211_SMPS_OFF:
533 		action_frame->u.action.u.ht_smps.smps_control =
534 				WLAN_HT_SMPS_CONTROL_DISABLED;
535 		break;
536 	case IEEE80211_SMPS_STATIC:
537 		action_frame->u.action.u.ht_smps.smps_control =
538 				WLAN_HT_SMPS_CONTROL_STATIC;
539 		break;
540 	case IEEE80211_SMPS_DYNAMIC:
541 		action_frame->u.action.u.ht_smps.smps_control =
542 				WLAN_HT_SMPS_CONTROL_DYNAMIC;
543 		break;
544 	}
545 
546 	/* we'll do more on status of this frame */
547 	IEEE80211_SKB_CB(skb)->flags |= IEEE80211_TX_CTL_REQ_TX_STATUS;
548 	ieee80211_tx_skb(sdata, skb);
549 
550 	return 0;
551 }
552 
553 void ieee80211_request_smps(struct ieee80211_vif *vif, unsigned int link_id,
554 			    enum ieee80211_smps_mode smps_mode)
555 {
556 	struct ieee80211_sub_if_data *sdata = vif_to_sdata(vif);
557 	struct ieee80211_link_data *link;
558 
559 	if (WARN_ON_ONCE(vif->type != NL80211_IFTYPE_STATION))
560 		return;
561 
562 	rcu_read_lock();
563 	link = rcu_dereference(sdata->link[link_id]);
564 	if (WARN_ON(!link))
565 		goto out;
566 
567 	if (link->u.mgd.driver_smps_mode == smps_mode)
568 		goto out;
569 
570 	link->u.mgd.driver_smps_mode = smps_mode;
571 	ieee80211_queue_work(&sdata->local->hw, &link->u.mgd.request_smps_work);
572 out:
573 	rcu_read_unlock();
574 }
575 /* this might change ... don't want non-open drivers using it */
576 EXPORT_SYMBOL_GPL(ieee80211_request_smps);
577